<?php
/**
* Style Engine: WP_Style_Engine_Processor class
*
* @package WordPress
* @subpackage StyleEngine
* @since 6.1.0
*/
/**
* Core class used to compile styles from stores or collection of CSS rules.
*
* @since 6.1.0
*/
#[AllowDynamicProperties]
class WP_Style_Engine_Processor {
/**
* A collection of Style Engine Store objects.
*
* @since 6.1.0
* @var WP_Style_Engine_CSS_Rules_Store[]
*/
protected $stores = array();
/**
* The set of CSS rules that this processor will work on.
*
* @since 6.1.0
* @var WP_Style_Engine_CSS_Rule[]
*/
protected $css_rules = array();
/**
* Adds a store to the processor.
*
* @since 6.1.0
*
* @param WP_Style_Engine_CSS_Rules_Store $store The store to add.
* @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
*/
public function add_store( $store ) {
if ( ! $store instanceof WP_Style_Engine_CSS_Rules_Store ) {
_doing_it_wrong(
__METHOD__,
__( '$store must be an instance of WP_Style_Engine_CSS_Rules_Store' ),
'6.1.0'
);
return $this;
}
$this->stores[ $store->get_name() ] = $store;
return $this;
}
/**
* Adds rules to be processed.
*
* @since 6.1.0
* @since 6.6.0 Added support for rules_group.
*
* @param WP_Style_Engine_CSS_Rule|WP_Style_Engine_CSS_Rule[] $css_rules A single, or an array of,
* WP_Style_Engine_CSS_Rule objects
* from a store or otherwise.
* @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
*/
public function add_rules( $css_rules ) {
if ( ! is_array( $css_rules ) ) {
$css_rules = array( $css_rules );
}
foreach ( $css_rules as $rule ) {
$selector = $rule->get_selector();
$rules_group = $rule->get_rules_group();
/**
* If there is a rules_group and it already exists in the css_rules array,
* add the rule to it.
* Otherwise, create a new entry for the rules_group.
*/
if ( ! empty( $rules_group ) ) {
if ( isset( $this->css_rules[ "$rules_group $selector" ] ) ) {
$this->css_rules[ "$rules_group $selector" ]->add_declarations( $rule->get_declarations() );
continue;
}
$this->css_rules[ "$rules_group $selector" ] = $rule;
continue;
}
// If the selector already exists, add the declarations to it.
if ( isset( $this->css_rules[ $selector ] ) ) {
$this->css_rules[ $selector ]->add_declarations( $rule->get_declarations() );
continue;
}
$this->css_rules[ $rule->get_selector() ] = $rule;
}
return $this;
}
/**
* Gets the CSS rules as a string.
*
* @since 6.1.0
* @since 6.4.0 The Optimization is no longer the default.
*
* @param array $options {
* Optional. An array of options. Default empty array.
*
* @type bool $optimize Whether to optimize the CSS output, e.g. combine rules.
* Default false.
* @type bool $prettify Whether to add new lines and indents to output.
* Defaults to whether the `SCRIPT_DEBUG` constant is defined.
* }
* @return string The computed CSS.
*/
public function get_css( $options = array() ) {
$defaults = array(
'optimize' => false,
'prettify' => defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG,
);
$options = wp_parse_args( $options, $defaults );
// If we have stores, get the rules from them.
foreach ( $this->stores as $store ) {
$this->add_rules( $store->get_all_rules() );
}
// Combine CSS selectors that have identical declarations.
if ( true === $options['optimize'] ) {
$this->combine_rules_selectors();
}
// Build the CSS.
$css = '';
foreach ( $this->css_rules as $rule ) {
// See class WP_Style_Engine_CSS_Rule for the get_css method.
$css .= $rule->get_css( $options['prettify'] );
$css .= $options['prettify'] ? "\n" : '';
}
return $css;
}
/**
* Combines selectors from the rules store when they have the same styles.
*
* @since 6.1.0
*/
private function combine_rules_selectors() {
// Build an array of selectors along with the JSON-ified styles to make comparisons easier.
$selectors_json = array();
foreach ( $this->css_rules as $rule ) {
$declarations = $rule->get_declarations()->get_declarations();
ksort( $declarations );
$selectors_json[ $rule->get_selector() ] = wp_json_encode( $declarations );
}
// Combine selectors that have the same styles.
foreach ( $selectors_json as $selector => $json ) {
// Get selectors that use the same styles.
$duplicates = array_keys( $selectors_json, $json, true );
// Skip if there are no duplicates.
if ( 1 >= count( $duplicates ) ) {
continue;
}
$declarations = $this->css_rules[ $selector ]->get_declarations();
foreach ( $duplicates as $key ) {
// Unset the duplicates from the $selectors_json array to avoid looping through them as well.
unset( $selectors_json[ $key ] );
// Remove the rules from the rules collection.
unset( $this->css_rules[ $key ] );
}
// Create a new rule with the combined selectors.
$duplicate_selectors = implode( ',', $duplicates );
$this->css_rules[ $duplicate_selectors ] = new WP_Style_Engine_CSS_Rule( $duplicate_selectors, $declarations );
}
}
}